Last September, we published a “How To” for making your own biodiesel. We had huge response (mostly positive, some critical). Since then, gas prices have continued to rise, and things are not getting better where oil resources are concerned. Because of this, we’ve decided today to repost our recipe for biodiesel. Since the initial posting it’s been tweaked slightly in response to some reader feedback. Read on to learn how you can have a healthier, cheaper, more environmentally-friendly ride.
(image found on AtlanticBlog)
Remember, a diesel vehicle does not require any modification at all in order to run on biodiesel. Once you’re sure you’ve got a quality brew (or if you are lucky enough to live somewhere where biodiesel is available at the pump), you just fill up and go!
Two things to keep in mind before you begin:
1. The instructions here are not oversimplified, but neither are they spelled out down to the last detail. This is something you can do yourself (I have, many times), but it’s still a chemical process and the substance you create is going into your vehicle. So the first time you try it, keep someone with experience by your side, and be meticulous.
2. Many of the ingredients involved here are hazardous! You don’t want to blind, burn, or otherwise harm yourself or your friends, so use extreme caution!
A DIY GUIDE TO MAKING YOUR OWN BIODIESEL
I bought a 1983 Mercedes 300 Turbo Diesel in 2003 and began running it on biodiesel immediately. The mileage is equivilent to (and sometimes better than) that of regular diesel, the fuel is non-flammable, making travel safer, and I breathe easier in every way knowing that there are fewer greenhouse gases sprewing out of my tailpipe. On top of the practical benefits, it’s been a thrilling couple of years watching biodiesel move from the fringe to the mainstream, gaining validation from government officials and business trendspotters, and street cred from farmers and truckers (and Willie Nelson.
You don’t have to make biodiesel yourself to use it. In SF, I belonged to the San Francisco Biofuels Cooperative, a member owned consumer co-op that buys biodiesel in bulk from distributors around California. Biofuel Oasis, a women-owned biodiesel gas station in Berkeley, is also a crucial fueling site and biodiesel resource center for the Bay Area community. Now that I’m in Seattle, I can get biodiesel at a regular gas station, thanks to Propel Fuels.
There are co-ops, producers and distributors around the nation who sell high-quality biodiesel for anywhere from $2.50-$3.90 per gallon. You can also perform a modification to your car that will allow you to put waste vegetable oil straight into your tank without turning it into biodiesel, making your fuel absolutely free forever. But that is a “how-to” for another day…
While mixing up biodiesel is not much more complicated than baking a cake, it does use methanol and sodium hydroxide or lye, all of which are dangerous substances in their pure form. Wearing safety goggles and rubber gloves is highly recommended, and preparing your first batch under the supervision of someone with experience might be wise. Finally, just as eating badly made cake will cause trouble in your belly, a sub-par batch of biodiesel can do damage to your car. So be sure you’ve got it right before you pour!
The Goal: Chemically speaking, vegetable oil is a tri-glyceride. Through the process of making biodiesel, the glycerin in the oil is replaced with an alcohol molecule, in this case utilizing methanol. This reaction is called transesterification.
Preparation: To get started, you will need either waste or new vegetable oil. If you want to use waste oil, which supports the reuse aspect of biodiesel production and keeps the process local, you will need to go talk to someone at a nearby restaurant. Generally, restaurant owners are delighted to have you haul away a few gallons or more of their grease, because otherwise they pay a removal service to get rid of it. Some will even pour it into containers you provide so that you don’t have to siphon from their drums. If you aren’t ready to hunt down a supplier, you can buy a jug of oil at the store. But using virgin resources (and the plastic container they come in) is the less eco-friendly route, so for this purpose, we’ll discuss waste vegetable oil (WVO).
Ingredients and Supplies:
1 kitchen blender (that you can never again use for smoothies!)
3 beakers (one 1500ml, one 500ml and one 20ml)
Graduated syringe or eye dropper
A Petri dish
1+ gallons of waste vegetable oil (if you are using various sources, each source will have a different pH, so keep in mind that your findings need to be for a uniform batch)
5 grams Lye (KOH)
1 bottle Isopropyl Alcohol (Rubbing Alcohol)
1 liter Distilled Water
1 bottle Phenolphthalein Solution (pH indicator – available at pool/hot tub suppliers)
1 bottle of methanol (you can also use ethanol)
Step 1 – Titration: Titration helps determine how much catalyst you must add by indicating the acidity of your oil.
Measure out 1g of lye in your Petri dish. Dissolve into one liter of distilled water. In 20ml beaker, dissolve 1ml of vegetable oil into 10ml of isopropyl alcohol. Swirl or warm very gently to dissolve the oil into alcohol and make the solution clear. Add 2 drops of pH indicator to this mixture and swirl to dissolve. Using your syringe or eye dropper, add 1 ml (only!) of lye solution to the alcohol and oil solution. Continue adding 1 ml at a time, swirling continuously, until it turns hot pink and holds its color for at least ten seconds. The number of milliliters of lye solution used, plus 3.5, equals the number of grams of lye you’ll need per liter of oil.
Step 2 – Brewing:
Measure out 1 liter of filtered waste vegetable oil in your 1500ml beaker. Measure out 200ml of methanol in your 500ml beaker. Measure the number of grams of lye that you determined during titration in your Petri dish.
Pour methanol into your blender. Add lye. Blend at low speed until fully dissolved. This reaction creates sodium methoxide. Because of rapid evaporation, the rest of the process must be done straightaway. Be careful not to inhale or ingest this stuff!
Pour filtered vegetable oil into sodium methoxide solution in blender and blend for fifteen to twenty minutes. After blending, the mixture must be left alone to settle for at least eight hours, at which point you will have two layers: glycerin on the bottom and biodiesel on top. The biodiesel (which is non-toxic) goes in your tank, and if you treat the glycerin to remove traces of methanol, it, too, becomes a harmless substance which, if you are exceptionally industrious, can be used to make soap. You’ve reincarnated grease into two phenomenally useful substances. Amazing!
Whether you make it yourself or buy it, getting on the road with biodiesel is easy. If you already own a diesel vehicle, you can do it today. For more info on biodiesel or to get involved, check out the links below:
Iowa State biodiesel site (if you want nitty-gritty scientific details)
Excellent FAQ on Biodiesel at www.metaefficient.com